Are you a developer? A designer? Illustrator? Animator? Something else in the creative world? I don’t even care and you shouldn’t either. Side project will benefit you anyway, even if the side project has nothing to do with your day-to-day job.
“Practice makes perfect!”. It’s a great way to increase your skills.
If there aren’t any ideas to get started, then don’t push it. It should be something you really enjoy doing without feeling like an obligation. If you need to force yourself to work on a side-project, simply drop it.
No-one is going to ask about your personal projects. It’s something you love doing and maybe, once it’s done, you can publish it online for other people to see and maybe even to use.
You can always google some creative app ideas or beginner guides and if you find something you like, you can tweak it any way you want. An example for me would be to follow a simple React tutorial, but actually making it with Vuejs instead of react. I love Vuejs more than react and this way I can challenge myself to see if I can make the same react app in vue. It’s also a good method to compare both Vue and React to see how both frameworks are doing the same thing in their own way.
However, finding time for those side-projects ain’t always easy. But because a side project should be something you really love, and not something that feels obligated, it actually helps to work on it during breaks.
When I’m doing client work and feel like I’m losing the zone, I can hop on a side project to take a little break from work. This can be a bit dangerous as working on side-projects can be more fun than working on client work. Too bad we still need to make some moneys, and a side project is not going to do that right from the start.
A routine that works for me is waking up early and spend 1 hour on my personal project in the morning, before I do anything else. It actually helps me waking up happy and full of energy as I really want to get started on my project. Get that first cup of coffee at 6am and make it work!